This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. IV-drug abuse is a prominent risk factor for HIV infection and AIDS. Credible support can be found that opiates have no effect, exacerbate, or even inhibit AIDS progression. In a pilot study using the simian immunodeficiency virus (SIV) infected rhesus macaque model, we found that AIDS progression was slowed by morphine dependency. We have subsequently initiated a trial to further investigate the relationship between opiate dependency and AIDS progression.